In today's politically-charged climate in Washington, D.C., it's rare to find a program that has near universal bipartisan support among Democrats and Republicans. It's also unusual for a policy to bring together environmentalists, industry and government officials for a common cause, much less one that actually provides a $13 to $1 positive return on investment to taxpayers and the federal government.

This unique program is called the Diesel Emissions Reduction Act and it was created to improve America's air quality by upgrading and modernizing older diesel engines and equipment through engine replacements and the application of new exhaust emissions filters and catalysts.

DERA is considered vitally important by government, industry and environmental officials as it can fund upgrades that reduce emission in older engines by up to 90%. Even the National Academy of Sciences calls DERA one of the most cost effective air quality projects in the nation.

Why? Diesel engines last a long time and play a vital role in key sectors of the Wisconsin and national economy. Wisconsin is one of the top 10 agricultural states in the United States and relies heavily on off-road diesel farm machinery. Over two-thirds of the more than 35,000 pieces of construction equipment in the state and virtually all of the truck and rail freight and passenger trains are diesel powered. Wisconsin's key commerce centers - the 15 commercial ports - handle more than 44 million tons of freight each year and the ships and equipment used in the ports are almost exclusively diesel powered.

Three Wisconsin organizations - the state Department of Natural Resources, the Associated General Contractors of Greater Milwaukee, and the Leonardo Academy in Madison - have recently been selected to receive DERA funding for new clean diesel projects.

These projects included upgrades of older diesel school buses, work boat engines, construction equipment and municipal buses with the most modern clean diesel retrofit technologies to reduce emissions.

In addition, Milwaukee County recently unveiled 90 new clean diesel buses that were partially funded with DERA money in the federal stimulus package.

But there's a problem: DERA will disappear next year if it isn't reauthorized by Congress. Sens. Thomas Carper (D-Del.) and George Voinovich (R-Ohio) are crafting new legislation to extend and improve the program, but they will need assistance to pass the bill by the 2011 deadline.

DERA was enacted in 2005 with strong bipartisan support to reduce emissions from existing diesel engines. It is an innovative voluntary program of national and state grants and loans for the installation of the most modern technologies for existing diesel vehicles and engines.

These DERA upgrades are important because the low-emission standards that began in 2007 don't apply to the more than 11 million pieces of diesel equipment and vehicles that were already in use. This is no small matter because diesel engines are extremely durable and it is not uncommon for it to take 20 to 30 years to turn over an entire fleet. A farm tractor, for example, can easily last 25 years.

Since its enactment, the program has been successful from an economic and public health perspective, and it has yielded one of the greatest cost-benefit ratios of any federal program, according to both the Office of Management and Budget and the Environmental Protection Agency.

Air pollution poses a serious threat to our nation's health. Public health organizations like the American Lung Association of the Upper Midwest work on DERA-funded projects to ensure that the air is clean and safe. Of special concern are the effects of diesel air pollution on the health of vulnerable populations that have respiratory disease and lung cancer. Through this effort, substantive benefits to the environment and public health are being realized on local and regional levels.

Nationally, DERA is supported by a unique coalition of more than 150 environmental and public health organizations, industry representatives, and state and local government associations including the National Association of Clean Air Agencies and Natural Resources Defense Council. These groups are urging Congress to reauthorize the DERA program this year with no shortage of eligible projects needing funding.

Our coalition of Wisconsin and national organizations are continuing to work with Congress to ensure continued funding for clean diesel retrofit projects this year, as well as for DERA's reauthorization. As we all work for a clean energy future, clean diesel is playing a major role in improving America's air quality.

Allen Schaeffer is the executive director of the Diesel Technology Forum in Frederick, Md., and Angela Tin is the vice president of environmental health for the American Lung Association of the Upper Midwest.